Simplified Thermal Model for Absolute Radiometer Simulation

2021 ◽  
Vol 143 (5) ◽  
Author(s):  
Andre Godoi Lopes ◽  
Ricardo Toshiyuki Irita ◽  
Luiz Angelo Berni ◽  
Waldeir Amaral Vilela ◽  
Graziela da Silva Savonov ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Solar Radiation ◽  
Thermal Behavior ◽  
Solar Irradiance ◽  
Thermal Model ◽  
Thermal Contact ◽  
Total Solar Irradiance ◽  
Space Environment ◽  
Simplified Model ◽  
Material Volume

Abstract The study of solar radiation in space has become something necessary, motivating the launch of radiometers on board satellites dedicated to perform total solar irradiance (TSI) measurements and to build a record of their behavior over the years, thus making these data essential for meteorology and climatology. In this study, we propose a simplified model to understand the thermal behavior of absolute radiometers, which are used in this type of measurement. The model considers the heat transfer among parts through conduction and loss only by radiation since the instrument operates in a space environment. The goal is to understand how each component interferes with sensitivity and response time of the instrument depending on its design, material, volume, and thermal contact. The model was applied to data generated by a prototype for validation.

Thermal Contact Electronic Packaging in Solar Pointing Space Environment

1991 ◽  
Vol 113 (1) ◽  
pp. 42-50 ◽  
Author(s):  
Kurt O. Lund ◽  
Anthony M. Colangelo ◽  
Gregory S. McKim
Keyword(s):  
Heat Transfer ◽  
Space Shuttle ◽  
Thermal Contact ◽  
Thermal Modeling ◽  
Radiation Heat Transfer ◽  
Thermal Design ◽  
Space Environment ◽  
Radiation Heat ◽  
Flow Paths ◽  
Flux Intensity

A thermal design for a solar pointing Space Shuttle mission is presented. The apparatus, which will measure solar flux intensity variations, contains sensors and data acquisition electronics which must be maintained within certain temperature constraints. The thermal design, which utilizes parallel heat flow paths and conduction fins to reject dissipated heat, is shown by finite difference thermal modeling to maintain component temperatures within these constraints. In the thermal modeling, arithmetic nodes are used to represent surface radiosity for radiation heat transfer. Also, the concept of mean fin conduction length and effective fin capacitance are introduced as means of simplifying the model representation of the conduction fins. An experiment was conducted to evaluate the chip/fin contact conductance.

scholarly journals Science Highlights and Final Updates from 17 Years of Total Solar Irradiance Measurements from the SOlar Radiation and Climate Experiment/Total Irradiance Monitor (SORCE/TIM)

Solar Physics ◽  
2021 ◽  
Vol 296 (9) ◽  
Author(s):  
Greg Kopp
Keyword(s):  
Solar Radiation ◽  
Solar Irradiance ◽  
High Sensitivity ◽  
Total Solar Irradiance ◽  
Low Noise ◽  
Final Data ◽  
Total Irradiance ◽  
Noise Measurements ◽  
Irradiance Data ◽  
Measurement Record

AbstractThe final version (V.19) of the total solar irradiance data from the SOlar Radiation and Climate Experiment (SORCE) Total Irradiance Monitor has been released. This version includes all calibrations updated to the end of the mission and provides irradiance data from 25 February 2003 through 25 February 2020. These final calibrations are presented along with the resulting final data products. An overview of the on-orbit operations timeline is provided as well as the associated changes in the time-dependent uncertainties. Scientific highlights from the instrument are also presented. These include the establishment of a new, lower TSI value; accuracy improvements to other TSI instruments via a new calibration facility; the lowest on-orbit noise (for high sensitivity to solar variability) of any TSI instrument; the best inherent stability of any on-orbit TSI instrument; a lengthy (17-year) measurement record benefitting from these stable, low-noise measurements; the first reported detection of a solar flare in TSI; and observations of two Venus transits and four Mercury transits.

scholarly journals Overview of the Solar Radiation and Climate Experiment (SORCE) Seventeen-Year Mission

Solar Physics ◽  
2021 ◽  
Vol 296 (8) ◽  
Author(s):  
Thomas N. Woods ◽  
Jerald W. Harder ◽  
Greg Kopp ◽  
Debra McCabe ◽  
Gary Rottman ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Solar Irradiance ◽  
Near Infrared ◽  
Total Solar Irradiance ◽  
Spectral Irradiance ◽  
Climate Data ◽  
Science Data ◽  
Near Ultraviolet ◽  
Battery Capacity ◽  
Data Gap

AbstractThe Solar Radiation and Climate Experiment (SORCE) was a NASA mission that operated from 2003 to 2020 to provide key climate-monitoring measurements of total solar irradiance (TSI) and solar spectral irradiance (SSI). Three important accomplishments of the SORCE mission are i) the continuation of the 42-year-long TSI climate data record, ii) the continuation of the ultraviolet SSI record, and iii) the initiation of the near-ultraviolet, visible, and near-infrared SSI records. All of the SORCE instruments functioned well over the 17-year mission, which far exceeded its five-year prime mission goal. The SORCE spacecraft, having mostly redundant subsystems, was also robust over the mission. The end of the SORCE mission was a planned passivation of the spacecraft following a successful two-year overlap with the NASA Total and Spectral Solar Irradiance Sensor (TSIS) mission, which continues the TSI and SSI climate records. There were a couple of instrument anomalies and a few spacecraft anomalies during SORCE’s long mission, but operational changes and updates to flight software enabled SORCE to remain productive to the end of its mission. The most challenging of the anomalies was the degradation of the battery capacity that began to impact operations in 2009 and was the cause for the largest SORCE data gap (August 2013 – February 2014). An overview of the SORCE mission is provided with a couple of science highlights and a discussion of flight anomalies that impacted the solar observations. Companion articles about the SORCE instruments and their final science data-processing algorithms provide additional details about the instrument measurements over the duration of the mission.

scholarly journals Solar Radiation in the Arctic during the Early Twentieth-Century Warming (1921–50): Presenting a Compilation of Newly Available Data

2021 ◽  
Vol 34 (1) ◽  
pp. 21-37
Author(s):  
R. Przybylak ◽  
P. N. Svyashchennikov ◽  
J. Uscka-Kowalkowska ◽  
P. Wyszyński
Keyword(s):  
Twentieth Century ◽  
Solar Radiation ◽  
Solar Irradiance ◽  
Global Solar Radiation ◽  
Total Solar Irradiance ◽  
The Arctic ◽  
Data Series ◽  
Radiation Balance ◽  
Radiation Data ◽  
Early Twentieth Century

AbstractThe early twentieth-century warming (ETCW), defined as occurring within the period 1921–50, saw a clear increase in actinometric observations in the Arctic. Nevertheless, information on radiation balance and its components at that time is still very limited in availability, and therefore large discrepancies exist among estimates of total solar irradiance forcing. To eliminate these uncertainties, all available solar radiation data for the Arctic need to be collected and processed. Better knowledge about incoming solar radiation (direct, diffuse, and global) should allow for more reliable estimation of the magnitude of total solar irradiance forcing, which can help, in turn, to more precisely and correctly explain the reasons for the ETCW in the Arctic. The paper summarizes our research into the availability of solar radiation data for the Arctic. An important part of this work is its detailed inventory of data series (including metadata) for the period before the mid-twentieth century. Based on the most reliable data series, general solar conditions in the Arctic during the ETCW are described. The character of solar radiation changes between the ETCW and present times, in particular after 2000, is also analyzed. Average annual global solar radiation in the Russian Arctic during the ETCW was slightly greater than in the period 1964–90 (by about 1–2 W·m−2) and was markedly greater than in the period 2001–19 (by about 16 W·m−2). Our results also reveal that in the period 1920–2019 three phases of solar radiation changes can be distinguished: a brightening phase (1921–50), a stabilization phase (1951–93), and a dimming phase (after 2000).

scholarly journals Alteration tendencies of upcoming on the upper atmosphere boundary solar radiation and theirs spatial localization

2019 ◽  
pp. 50-58
Author(s):  
V. M. Fedorov ◽  
S. A. Sokratov ◽  
D. M. Frolov
Keyword(s):  
Solar Activity ◽  
Solar Radiation ◽  
Solar Irradiance ◽  
Rotation Axis ◽  
Remote Sensing Data ◽  
Physical Nature ◽  
Total Solar Irradiance ◽  
Total Flow ◽  
The Earth

Satellite measurements of total flow of upcoming to the Earth solar radiation (Total solar irradiance) are performed since 1977. At present time continues measurement series of total flow of upcoming solar radiation are obtained. In long-term measurements of solar radiation the eleven-year cycle and its amplitude is revealed. However in regularity of solar radiation income to the Earth (without consideration of atmosphere) and spatial distribution of it along the Earth surface (solar climate of the Earth) two mechanisms having different physical nature are marked out. One mechanism is related to variation of solar activity. Another mechanism is defined by celestial mechanical processes varying elements of Earth orbit (Earth-Sun distance, tropical year duration, etc.), Earth rotation axis declination and related to it variation in Earth insolation. Performed calculations of Earth insolation related to celestial mechanical processes are the basis for differentiation of remote sensing data on total solar irradiance regarding mechanisms of different physical nature. The possibility of estimation of contribution of solar activity and celestial mechanical processes in variation of total flow of upcoming to the Earth solar radiation is created.

Optimization of thermal model and prediction of crystallinity during the laser-assisted tape winding process

2021 ◽  
pp. 073168442199213
Author(s):  
Zhengqi Kou ◽  
Jun Xiao ◽  
Dajun Huan ◽  
Kang Zhu ◽  
Lei Yan
Keyword(s):  
Heat Transfer ◽  
Thermal History ◽  
Thermal Model ◽  
Near Infrared ◽  
Thermal Contact ◽  
Measuring System ◽  
Thermoplastic Composites ◽  
Independent Experiment ◽  
Transfer Model ◽  
Element Analysis

Laser-assisted tape placement and tape winding represent the most advanced automated manufacturing technologies for thermoplastic composites. It is important to accurately predict the complete thermal history of the manufacturing process, on which many properties of the product are strongly dependent, such as interlaminar bonding strength and crystallization. In this article, a nonlinear two-dimensional transient heat transfer model was established in ANSYS APDL, and a new temperature closed-loop controlled near-infrared laser heat source was described. Most importantly, the thermal contact pairs were introduced following the activation of elements, and the value of interlaminar thermal contact resistance was obtained by fitting an independent experiment and finite element analysis, which greatly optimized the heat transfer process in the direction of thickness. The thermal model was verified by infrared cameras and an online temperature measuring system based on thermocouples. The results of thermal history are in good agreement with the experiment, which were input into the crystallization kinetics model to predict the evolution and distribution of crystallinity in the laser-assisted tape winding process. The calculated results are coincident with the differential scanning calorimeter test very well, and the crystallinity was about 17% higher than that before manufacturing.

scholarly journals The periodic variation of 6.7 days for total solar radiation

2009 ◽  
Vol 5 (S264) ◽  
pp. 84-86
Author(s):  
W. Q. Gan ◽  
Y. P. Li
Keyword(s):  
Magnetic Field ◽  
Solar Radiation ◽  
Power Spectrum ◽  
Solar Irradiance ◽  
Solar Magnetic Field ◽  
Solar Rotation ◽  
Periodic Variation ◽  
Total Solar Irradiance ◽  
Total Solar Radiation ◽  
Total Irradiance

AbstractAnalyzing the power spectrum of Total Solar Irradiance (TSI) for the period from 2003 February 25 to 2009 July 6, observed with the Total Irradiance Monitor (TIM) onboard SOlar Radiation and Climate Experiment (SORCE), we found that there are quite a number of periodic variations. The outstanding shortest one is the period of 6.7 days, about one fourth of the period of solar rotation. Checking the solar magnetic field for the same period of time observed with MDI onboard SOHO, we found that there is about 90 degree difference in longitude for the distribution of solar magnetic field. We therefore conclude that both the 90 degree difference in longitude for the distribution of solar magnetic field and the solar rotation are the reason resulting in the periodic variation of 6.7 days for the total solar radiation.

scholarly journals Exploring the Effects of Solar Radiation Management on Water Cycling in a Coupled Land–Atmosphere Model*

2016 ◽  
Vol 29 (7) ◽  
pp. 2635-2650 ◽  
Author(s):  
Katherine Dagon ◽  
Daniel P. Schrag
Keyword(s):  
Soil Moisture ◽  
Solar Radiation ◽  
Greenhouse Gas ◽  
Solar Irradiance ◽  
Total Solar Irradiance ◽  
Solar Radiation Management ◽  
Model Version ◽  
Water Cycling ◽  
Radiation Management ◽  
Global Mean

Abstract Solar radiation management (SRM) has been proposed as a form of geoengineering to reduce the climate effects of anthropogenic greenhouse gas emissions. Modeling studies have concluded that SRM, through a reduction in total solar irradiance by approximately 2%, roughly compensates for global mean temperature changes from a doubling of carbon dioxide concentrations. This paper examines the impact of SRM on the terrestrial hydrologic cycle using the Community Land Model, version 4, coupled to the Community Atmosphere Model, version 4, with reductions in solar radiation relative to simulations with present-day and elevated CO2 concentrations. There are significant global and regional impacts due to vegetation–climate interactions that are not compensated when reductions in total solar irradiance of 1%, 2%, and 3% are imposed on top of a doubling of present-day CO2 concentrations. Water cycling slows down under SRM, including decreases in global mean precipitation and evapotranspiration. Changes in runoff and soil moisture are spatially and temporally variable, with implications for local water availability. In the tropics, evapotranspiration decreases because of increases in vegetation water use efficiency. In northern midlatitudes, soil moisture increases when evapotranspiration decreases, with some exceptions during boreal summer. Changes in soil evaporation influence water cycling in the southern subtropics, rather than changes in transpiration. The hydrologic response to SRM is nonlinear, with global mean decreases greater than expected. These results imply that SRM may not compensate for higher greenhouse gas concentrations when one considers land–atmosphere interactions.

The Fengyun-3E/Joint Total Solar Irradiance Absolute Radiometer: Instrument Design, Characterization, and Calibration

Solar Physics ◽  
2021 ◽  
Vol 296 (3) ◽  
Author(s):  
Baoqi Song ◽  
Xin Ye ◽  
Wolfgang Finsterle ◽  
Manfred Gyo ◽  
Matthias Gander ◽  
...  
Keyword(s):  
Solar Irradiance ◽  
Total Solar Irradiance ◽  
Instrument Design
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